Developer.



PATENTED EEB. 17, 1903.

J. G. DUBLER.

DEVELOPER.

APP'LIOATION FILED DB0. 26. 1901,

I0 MODEL.

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UNITED STATES PATENT OEEICE.

JOHN GEORGE DUBLER, OF ST. LOUIS, MISSOURI.

DEVELOPER.

SPECIFICATION forming part of Letters Patent No. 721,029, dated February17, 1903.

Application filed December 26, 1901. Serial No. 87,197. (No model.)

To a/ZZ whom, t may concern,.-

Beit known that I, JOHN GEORGE DUBLER, a citizen of the United States,residing at St.. Louis, in the State of Missouri, have invented new anduseful Improvements in Developers, of which the following is aspecication.

This invention relates to a developer, and may be properly termed atechnique-developer, for use by students in piano-exercises, as Well aspupils in learning type-writing and other analogous operations; and thepurpose of the same is to produce a systematic development of strength,independence of action, and suppleness of all the muscles and joints inthe forearm and hand and also, byits particular shape and weight, tophysically improve the symmetry of the forearm by acting on the musclesand producing a graceful fullness to the form of the forearm.

The improved device has been devised after a very careful study andconsideration of the peculiarities and demands of the muscularorganization of the forearm and the correlativo dependence and functionsof the muscles or tendons of the hand and its digits.

The improved device has therefore been physiologically shaped, beingpatterned to lit a perfectly-formed well-developed arm in every detailwhile in the proper position for the easiest and best results whileplaying a piano.

The improved device causes an equal pressure on the muscles as theyexpand, exercising them individually when a finger is raised, with theresult that the developer causes a particular consciousness of thedistinct action with more of a certainty than ordinary movements create.As a result the relative sensory nerve becomes more sensitive to theaction of the muscles, and consequently eects an additional force andiiexibility to the articulation. Theweightof thedevelopercauses a slightcontraction of the great or ilexor muscle in the forearm, and when anattempt is made to raise a nger additional contraction of the relativemuscle causes a thicken-v ing or expansion of the distinct muscle-cord,which is the result desired to be obtained by the application of thedeveloper.

In the drawings, Figure l is a perspective view of a forearm and handshown elevated in relation to piano-keys, the improved developer beingapplied in operative position on the forearm. Fig. 2 is a detailperspective view of the improved developer. Fig. 3 is a front endelevation thereof. Fig. 4 is a transverse vertical section of the same.

Similar numerals of reference are employed to indicate correspondingparts in the several views.

The numeral 1 designates the body of the developer, which is constructedof suitable metal and will be made in different sizes and Widths to suitindividual requirements. The body l is of arcuate shape and open at thebottom and is also of such form -longitudinally as to accurately conformto the contour of the forearm, and with this end in view the rearportion or end 2 is of greater width than the front extremity 3, and onone side of the forward extremity an elongated concavity 4 is producedto fit snugly against that portion of the arm in rear of thewrist-joint.

It will be understood that the sides 5 of the developer are-smoothly andgradually curved or otherwise shaped to adapt the device for comfortableapplication to the forearm, and by having the bottom of the developeropen an application and removal thereof can 'be readily pursued.

, For ease and comfort in the use of the improved device it is providedwith a covering 6, of leather or other suitable material, the saidcovering being secured at the edges of the device. f Y

The improved device may be castor otherwise produced, and when appliedit virtually serves as a mold in connection with the arm to develop themuscles in both the arm and hand, the muscles of the latter beingstrengthened and improved by the reflex inliuence of the muscles in theforearm.

The improved device has been devised with the fact in view that thephysical and psychical processes require equal attention and separatecultivation, which is more apparent in piano playing than in anyotherart, as the full power of both are constantly required in executingdifficult passages or overcoming Well-known preliminary obstructions tothe beginner, and it is also obvious that neither one should beovertaxed to support the other.

Thought and action or sensory and motor nerves are required to act Withperfect composure, and it is self-evident that neither should suffer theloss of advantage by overexertion. By straining and exerting the sensorynerves and the attention to which in forcing the motor nerves to developtechnique of the fingers a habit is acquired Which will eventuallybecome an imaginary necessity, and all other success Will under suchconditions be secondary in their relation.

The improved device will tend to increase the strength, flexibility, andindependence of movement, as Well as more complete control, in the arms,wrists, and ngers, and Will develcp each linger in strength andtractability exclusive and independent of the other fingers, so thatscales and arpeggios may be played more rapidly and smoothly and agraceful position and movement result. Moreover, a positiveness andexactness of execution will be apparent from use of the improved deviceWhich Will be indicative of pre-V 2. As an improved article ofmanufacture,

a developer ot' the class set forth of arcuate form and of alongitudinal contour to conform to the shape of the forearm, thedeveloper being fully and continuously open at the bottom and having acovering thereover.

In testimony whereof I aflx my signature in presence of tWo Witnesses.

JOHN GEORGE DUBLER.

l/Vitnesses:

CHAs. KUHN, LARRY GERREN.

